Manhole top



Mar. 6, 3923.

C. l.. L! NCOLN MANHOLE TOP Filed Nov.

"lllllv-w Patented Mar. 6, 1923.

#fuiven s- PATENrorFIcE.-

CHESTER L LINCOLN, OF NEW YORK, N. Y.

MANI-Iona Tor.

Application filed November 22, 1921. Serial No. 516,923.

. To all whom t may concern.'

full, clear, and exact description of the ,in,

vention, which will enable others skilled in the artto whichit appertains to make and use the same. i' v My invention relates to manholeftops,

such as are used for street-openings, for.

sewers, electrical Vconduits and the like.

AOne vof the objects of my invention is to provide a manhole-top, adjustable relatively to the surface of thestreet, Iwhich will be simple 4and economical to manufacture,

and which shall beso constructed that itI will not accumulate dirt that will interfere.

with itsoperation or adjustability.

Anothenobject is to secure `strength and durability. i

My invention is illustrated in the drawings,.wherein F ig. 1 is a plan view havingl a portion of the cover broken away, and F ig. 2 is a sectionalview on the line 2 2 of Fig. 1.

The present-,invention is intended as a simplification of the construction shown in the patent to C. E. Tyler, No. 1,165,044, of I December 21, 1915, wherein adjustability with reference to the street surface is one of the principal features.

Referring to the drawings in detail, the numeral 3 represents the masonry of the chamber to which a manhole-top is applied; t represents the annular base section, having an outwardly extending flange 5 resting on. the masonry of the chamber, and

downwardly extending lugs 6 to prevent.

lateral displacementv of the base section. On the interior surface of the base section 4- are a series of posts 7, formed integrally therewith, the tops of which are inclined as at 8, to afford bearing surfaces for the inner section now to be referred to.

The innersection 9 has an annular portion 10 slightly smaller than the main part of the base section 4, so as to t in and rotate within the latter. The lower end of the annular portion 10 has a series of cutaway portions 11, each of which has an inclination corresponding tothe top of the posts 7. The inner section 9 is also lianged inwardly as at 12, to provide a seat for the `cover 13 and flanged outwardly,` as at 14:, to limitthe extent ofthe downward movement4 of thev inner,v section withinj'the base section et. Stop-lugs 15; limit the upward movement of the inner? section,`to prevent the same from jumping off the posts 7. A bracket 16 is provided to hold the bail of a cleaning-bucket. Theuoutwardly extend ing lugs 17 are used as rests uponthe street havement. l

Among other advantageswhich my invention presents over the art so far as I am aware of it, is the fact that the base sec-y tion 4 by reason of the plural-ity of posts 7 lpresents no ,pocket` in which dirt'or .other material may becomevlodged so` asto. in-

via

terfere with the eflicient operationA of the structure. In the lprior art, devices similar to mine reither present a lplurality, of such pockets between adjacent ratchet projections or l'in grooves between annular `anges. In

the disclosed embodiment of myinvention,

lif any extraneous material should become lodged on the lcam surface of one'of the posts 7, it would immediatelybe removed when the structure isadjusted to operative position.

A f rther advantage of my invention is that the posts .7 `act as strengthening ribs for the base section ll and thusrallow a great saving of materiall in the manufacturev of that section. Q

The operation is obvious from the foregoing description. The inner section is rotated to bring the cover up even with the surface of the street, and, as the lugs 1.7 are made to vrest upon the street pavement, further rotation will be vprevented by frictional engagement of said lugs with the pavement.

Having described my invention, what I claim as new is:

1. An extension or telescopio frame adapt ed to be used as a manhole cover, comprising a xed base member formed as a hollow cylinder, a hollow cylindrical member telescoping therein, lugs integral with said base` member and extending radially inwardly from the interior surface thereof, the upper surfaces of said lugs forming cams for moving said telescoping member axially relative to said base member, cam surfaces on the lower edge of said telescoping member for (3o-.acting with said cam surfaces on saidf' scoping member, said lugs also being spaced f I apart circumferentially of said base member a distance approximately equal to the length of a cam surface on the telescoping member, and downwardly extending stop lugs at the lower end of each of said cam surfaces.

2. ln a manhole-top construction, an annular base member adapted to have its lower surface rest on the masonry of a manhole, a series of vertical posts integral with said base member and projecting inwardly in cross-section from the inner annular surface of said base member, said posts having inclined top surfaces adapted to act as cams to properly adapt the manhole construction to pavements of various thicknesses, an inner annular member adapted to be supported by thc upper surfaces of a pavement and to fit rotatably into said base member, the lower edge of said inner annular member having a plurality of cam faces to correspond to the inclined tops of the posts, said posts being relatively narrow as compared to the length of one of said cam faces and downwardly extending stop lugs at one end of each of said cam faces.

3. An extension or telescopic frame adapted to be used as a manhole cover, comprising a fixed base member formed as a hollow cylinder, a hollow cylindrical member telescoping therein, lugs integral with said base member extending radially inwardly from the interior Asuriace thereof and spaced apart circumferentially of said base members, the upper surfaces of said lugs forming cams for moving said telescoping 'member axially relative to said base member, cam surfaces on the lower ecce of said telescoping member for co-aeting with said cam surfaces on said lugs, one of said cam surfaces being of much greater length than the. cam surface of one of said lugs, and means for limiting the rotary movement of said telescoping member.

Ll. ln a manhole-top construction, an annular base member adapted to have its lower surface rest on the masonry of a manhole, a series of vertical posts integral with said base member and projecting inwardly from the inner annular surface of said base mem ber, said posts having inclined top surfaces adapted to act as cams to properly adapt the manhole construction to pavements of various thicknesses,l an inner annular member adapted to be supported by the upper surface of a pavement and to lit rotatably into said base member, the lower edge of said inner annular member having a plurality ofcam faces to correspond to the inclined tops of the post-s, and downwardly extending stop lugs at one end of each of said cam faces.

. ln a manhole-top construction, an annular base member adapted to have its lower lsurface rest on the masonry of a manhole, a

series of vertical posts integral with said base member and projecting` inwardly in cross-section from the inner annular surface of said base member, said posts having top surfaces adapted to act as cams to properly adapt the manhole construction to pavements of various thicknesses, an inner annular member adapted to be supported by the upper surface of a pavement and to lit rotatably into said base member, said posts being spaced apart about the base member, and a plurality of cams formed at the lower edge of said inner annular member, said cams being of greater length than the top surfaces of said posts.

CHESTER L. LINCOLN. 

